In-vitro adherence of oral streptococci in the presence of sucrose and its relationship to cariogenicity in the rat

Abstract

Streptococcus sanguis I gave a significantly greater percentage coverage (cell-pellicle attachment) of saliva-coated glass in the presence of sucrose than did Strep. sanguis II ( p < 0.025), and both these gave greater percentage coverages than the other species tested, between which no significant differences were noted. There was a large number of significant differences in clump size (cell-cell attachment) between species-pairs. Among the mutans streptococci, there were significant differences in the percentage coverage between Streptococcus rattus / Streptococcus mutans ( p < 0.05) and Strep. rattus/Streptococcus sobrinus ( p < 0.01), and in clump size between all species-pairs with the exception of Streptococcus cricetus or Strep. sobrinus and Strep. mutans.The rank order of species in relation to fissure caries was mutans streptococci > Streptococcus salivarius > Streptococcus milleri > Strep. sanguis > Streptococcus faecalis > Streptococcus mitis > Streptococcus lactis. There was a significant correlation between percentage coverage in vitro and fissure caries in vivo for strains of Strep. sanguis ( p < 0.05) and pooled strains of Strep. mitis and Strep. sanguis ( p < 0.01). On comparing data for adherence in the presence or the absence of sucrose, the sugar had no effect on the percentage coverage of the seven species tested, but significantly increased the clump size of the mutans streptococci ( p < 0.01) and Strep. sanguis ( p < 0.05).